Röderstein did amasing parts. Try the KP1822 capacitor if you can get them.
Simon, i could send you some Dale RS55 unmagnetic if you like.
Simon, i could send you some Dale RS55 unmagnetic if you like.
Wait a minute.
The resistors were supposedly a Holco, a Resista and a Mills. But the third resistor is given as a "PRP 9372." I can only find this number associated with Precision Resistive Products. It doesn't match anything made by Mills.
So which is it? Is it a PRP resistor or a Mills resistor?
se
The resistors were supposedly a Holco, a Resista and a Mills. But the third resistor is given as a "PRP 9372." I can only find this number associated with Precision Resistive Products. It doesn't match anything made by Mills.
So which is it? Is it a PRP resistor or a Mills resistor?
se
Simon, we should try more Resista resistors, perhaps that was an accidental making. The new Resista resistors should be much like the Dale. Michael Percy might be able to sell you a few OLD units. Use my name, when you ask, and insist on only OLD stock.
The PRP 'should' be a good wirewound, but you never know.
The PRP 'should' be a good wirewound, but you never know.
Are you sure about that number, not a typo ?
My oldy Roederstein catalogs do not mention it, best Roe caps i traced in the 1980s were the radial Ero KP1830 for values up to 33nF and the axial Ero KP1832 for larger up to 0.68uF.
Seems odd that Roederstein manufactured an identical KP series number along with the MKT1822, not exactly "heimatlich".
Definitely a good idea. While promising, experiments with a sample of one aren't very convincing.
Steve,
You only read the fine print on the first 2 graphs, I did not show the PRP. Please send my usual consulting fee for more data🙂!
John,
I did get the vintage Resista from M Percy. I have 10 samples. For most of the others I get some samples as bulk and some as tape/reel that way I know they were not all produced at the same time. I have some Yaego's 1/4 W MF 1% with the same part number but some are marked "China" and the others "Taiwan". They do not measure the same.
Most resistor types measure better with increase in wattage rating. That is why the Mills is so interesting. It may be shedding light on wire/cable distortion!
The Vishay Dale military style large body Metal Films come in 25, 50 and 100 PPM. I have lots of variants, After completing the runs on all of the samples I will remeasure some of them to confirm the results are the same from start to finish. A quick retest is the same.
Yes, the Röderstein are KP1832. I have them in 1.5nF-1200V, 10nF - 1500V, 18nF - 2000V.
They made also MKP1842 and MKP1839 with higher values that are also very good.
They made also MKP1842 and MKP1839 with higher values that are also very good.
Germans usually make better than usual quality stuff. I have a lot of Siemens polystyrene from the past, old Roderstein resistors, etc. I tend to use RELIABLE caps, made in USA, for serious caps. I should not tell you this, as you are a potential competitor, but we are also colleagues.
My somewhat ignorant impression is/was that the so called "non-inductive" wirewounds are not reactive up to some relatively low frequency when we are into the RF range... is this correct?
_-_-bear
_-_-bear
They are pretty good, but with feedback amplifiers, I would expect some compromise in stability.
I think I have a pretty good understanding of Simon's measurement technique and its pros and cons. I do have a concern that two slightly nonlinear devices that are almost perfectly matched will cancel their nonlinearities in the middle. Also given that the distortions are in the parts per billion range and the setup will amplify in a nonlinear way any impedance differences at higher frequencies it would need the parts to be similar to a very high degree. Even the balancing (lead compensator) network will impact the overall performance at this level of resolution. I have played around with this type of measurement for DC calibration if resistive divider networks to the ppm level and its very sensitive to setup even at DC. At AC there are issues about stray C's and L's not to mention the balance of the differential amps input circuitry. Attempting to duplicate John Curl's cap measurements was quite the challenge. For an in depth discussion read this http://assets.fluke.com/manuals/720A____imeng0200.pdf
I sent Simon a set of 20 matched (seem to be to about .01%) pairs of 10K Vishay Z102 resistors. These all measure in the -165 dB + range on my CLT 1. It will be interesting to see how they work in Simon's setup.
As for wirewound Resistors and high frequencies- the HP 400 series of AC voltmeters (1% accuracy to 4 MHz) used wirewound resistors on mica cards on the input divider network. Its all relatively high impedance so stray C is a big issue but the resistors were able to meet those very stringent requirements, and I would not write them off today either.
I sent Simon a set of 20 matched (seem to be to about .01%) pairs of 10K Vishay Z102 resistors. These all measure in the -165 dB + range on my CLT 1. It will be interesting to see how they work in Simon's setup.
As for wirewound Resistors and high frequencies- the HP 400 series of AC voltmeters (1% accuracy to 4 MHz) used wirewound resistors on mica cards on the input divider network. Its all relatively high impedance so stray C is a big issue but the resistors were able to meet those very stringent requirements, and I would not write them off today either.
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Demian,
Got em. 20 dual 10Ks, 5 3.33K, 2 1K rect, 2 10K axial, 1 1KWW, and 1 1K caddock.
As my current setup is for a 10K bridge with the DUT upper left and lower right I will have teat the duals as singles, The 3.33K I will use 3 in series against a reference, the 1Ks will have to wait for a new setup. I have so far gone through my "Audio", military, commercial MF, and Carbon film samples. I should finish the carbon comps tommorrow and start on the surface mounts, so I should have your data by Friday for the easy ones!
Got em. 20 dual 10Ks, 5 3.33K, 2 1K rect, 2 10K axial, 1 1KWW, and 1 1K caddock.
As my current setup is for a 10K bridge with the DUT upper left and lower right I will have teat the duals as singles, The 3.33K I will use 3 in series against a reference, the 1Ks will have to wait for a new setup. I have so far gone through my "Audio", military, commercial MF, and Carbon film samples. I should finish the carbon comps tommorrow and start on the surface mounts, so I should have your data by Friday for the easy ones!
We will use RELCAP capacitors too in our American made Sonics speakers.
I talked to the designer at CES and he told me that he buyes the raw plastic foils in Germany so it is a kind of German-American friendship project.
I talked to the designer at CES and he told me that he buyes the raw plastic foils in Germany so it is a kind of German-American friendship project.
Simon,
I somehow though you were using 1K as your target. No need to check 40 resistors unless you want some statistics on s102 Vishay chips. You could also set up two of the Vishays as a bridge and see what you find as a balance.
If work is light this week I'll build a similar fixture and see what I learn.
I somehow though you were using 1K as your target. No need to check 40 resistors unless you want some statistics on s102 Vishay chips. You could also set up two of the Vishays as a bridge and see what you find as a balance.
If work is light this week I'll build a similar fixture and see what I learn.
Never mind, I am running 1K's at the moment. Should be able to test them all. I will run the vishay 10K's all by them selves and make a 1k set for comparison.
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